Bolster damping arrangement for railway car trucks



BOLSTER DAMPING ARRANGEMENT FOR RAILWAY CAR TRUCKS Filed Feb. 2, 1956 C. W. WULFF Feb. '17, 1959 5 Sheets-Sheet l y 9/ MAJ, Wt 77?: yfii 5,

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BOLSTER DAMPING ARRANGEMENT FOR RAILWAY CAR TRUCKS Filed Feb. 2, 1956 5 Sheets-Sheet 2 l E Y I I kgmar l I F L: W T W E "iii 5 Ijfi' 'IIE f; wi

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BOLSTER DAMPING ARRANGEMENT FOR RAILWAY CAR TRUCKS 5 Sheets-Sheet 3 Feb. 17, 1959 c. w. WULFF 2,873,690

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BOLSTER DAMPING ARRANGEMENT FOR RAILWAY CAR TRUCKS Cal W. Wullf, Chicago, 111., assignor to Holland'Company, Chicago, 111., a corporation of Illinois Application February 2, 1956, Serial No. 562,993

3 Claims. (Cl. 105-197) This invention relates to a bolster damping arrange ment for use on newly constructed car trucks, and more particularly is concerned with a novel bolster construction which accommodates and cooperates with an improved form of damping device that is in frictional en gagement with the opposed vertical surfaces of the side frame columns that fiank the bolster.

Bolster damping constructions consisting generally of axially loaded flat faced friction blocks cooperating with wear plates mounted on the opposed vertical faces of the side frame columns have previously been employed in order to take advantage ofcertain features peculiar to this arrangement. The term axially loaded as used herein is intended to mean that the axis of the control spring extends in a direction normal to the plane of the flat friction surfaces of the friction block and wear plate.

Some of the advantages of an. axially loaded damping system are: the arrangement exerts a three way control of bolster movement in that undue vertical, lateral, and longitudinal movements of the bolster relative to the side frame are all subjected to a stabilizing action; the arrangement provides a constant stabilizing friction force on both the compression and release vertical motions of the bolster supporting springs; and the arrangement utilizes fiat friction faces to avoid any wedge action and render the friction system free of friction block sticking and bombarding and the resultant damage to the operating parts.

The principal object of the present invention is to provide an improved construction embodyingan axially loaded friction block system' that materially enhances the inherent advantages of such a system andoffers additional operating advantages Whilesimultaneouslysimplifying manufacturing and handling procedures and consequently reducing manufacturing and installation costs. 7

Briefly, this is accomplished by providing 'a novel bolster construction having integral, large size, housing arrangements for the friction block and-associated control spring. The greater strength inherent inv this one piece construction permits the use of larger sized friction apparatus and is arranged to accommodate this larger sized apparatus within a bolster having standard overall dimensions. The bolster is of one piece cast construction and by properly regulating the coring operation during the construction of the bolster a moreaccurate and uniform relationship may be maintained between the friction housings and the bolster side faces and this relationship in cooperation with additional guiding and alignment housing portions provided in the bolster for cooperation with the friction blocks introduces an accuracy into the construction not heretofore realizable and materially improves the operating characteristics of the axially loaded system.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings forming a p-art'of this atent ice specification and in which like numerals are employed to designate like parts throughout the same,

Fig. 1 is a fragmentary side elevational view of a freight car truck of the spring plankless type equipped with the bolster damping construction of this invention, and with parts broken away to better disclose the action of the damping arrangement;

Fig. 2 is an enlarged sectional view taken in the vertical plane of line 22 of Fig. 1;

Fig. 3 isan enlarged fragmentary plan view partly in section and taken in the vertical planes of line 3-3 of Fig. 1;

Fig. 4 is a side sectional view through the-housing and apparatus of the friction damping system and is'taken in the vertical plane of line 4-4 of Fig. 2;

Figs. 5 and 6 are exploded plan and side views; respectively, partly in section, of the parts of the friction damping system and illustrating the free height of the control spring;

Fig. 7 is a fragmentary perspective view with parts broken away showing the one piece cast construction of the bolster and illustrating the cooperation between the friction block and its housing;

Figs. 8 and 9 are plan and side views, respectively, partly in section, and illustrating the relationship of the parts when held retracted by a retaining key;

Fig. 10 is a front elevational view partly in section and is taken generally in the vertical plane of'the' line 10-10 of Fig. 8; and

Fig. 11 is a side sectional view similar to Fig. 4 but showing a modification of the invention wherein the spring barrel extends to the bolster center rib which func tions as a spring seat.

Referring now to Fig; 1, there is shown a conventional side frame of a freight car truck. The side frame includes a compression member 21, atension member 22 and spaced side columns 24 that define a bolster opening 25 within which the truck bolster 26 rides. The bolster is supported on a plurality of springs 27 which rest upon a spring seat 28 at the bottom of the bolster opening. The invention is described herein in connection with a truck ofv the spring plankless type but it is fully as applicable to a spring plank truck.

In the present invention the opposite ends of the bolster are each provided with a pair of friction housings, designated generally as 30, arranged inv back to back relationship and they mount friction devices or apparatus for cooperation with the opposed vertical faces of the side frame columns 24. For this purpose the side frame columns are provided with wear plates 32 which are preferably welded thereon'and which provide opposed vertically disposed flat friction faces.

The general arrangement of the integrally cast friction housings of the invention is best seen in Fig. 7. The bolster is shown as consisting of the usual top wall 33, bottom wall 34-, side walls 35, center rib 36, and guide flanges 37. The housing for the friction damping apparatus consists of a cylindrical spring barrel portion39 defining a spring barrel chamber, a friction block portion 40 defining a friction block chamber opening through the bolster side wall anda guide and retainer portion 41 defining a guide chamber located rearwardly of the friction block portion and above the spring barrel portion and in open communication with each of these. As is evident in Fig. 7, the portion of the bolster side wall between the guide fianges' 37 is broken out to form a rectangular opening corresponding in size and shape to the friction block portion and through which the friction block 43 engages the wear plate carried by the side frame column.

As shown in Figs; 2-6 the springbarrel portion of the asraeao Q friction housing consists of a longitudinally extending cylindrical wall 45, the sides of which are slotted as indicated at 46 for ease of spring inspection, and the bottom of which is slotted as indicated at 47, to provide appropriate drainage facilities, and a rear wall 48 which provides a spring seat for a helical control spring 50. The front portion of the spring barrel merges with laterally directed wall portions 52 which are connected at their extremities with outwardly extending longitudinal wall portions 53. Bolster wall portions 33, 34, 52 and 53 define the main housing for friction block 43.

The friction block 43 consists of a large, main block like portion 55 and a rearwardly extending rectangularly shaped portion 56 that functions as an aligning guide and cooperates with a retaining key element. The main portion 55 of the friction block is formed with a rearwa'rdly opening circular recess 57 that forms a convenient seat for the front end of the control spring 50. The guide 56 includes a depending rear wall 61 and laterally spaced side arms 62 connecting the rear wall to the main friction block 55. The side arms are provided with longitudinal retaining slots 63.

The control spring is shown in its loaded operating condition in Figs. 2, 3, and 4 and in its expanded free height in Figs. 5 and 6.

The guide housing portion 41 for the guide 56 consists of a rear lateral wall 59 and longtiudinally extending side walls 60 and is bounded by the top wall 33 of the bolster. The housing portions and 41 should be of substantially the same size and shape as the friction block 55 and its guide' 56, respectively. The side walls 53 of the friction block housing and the side Walls 60 of the guide housing are formed with flat smooth inner surfaces that extend exactly normal to the face of the side wall 35 of the -bolster and this accurate alignment is made possible by casting the friction housing portions integrally with the bolster walls. It is relatively simple to maintain accurate control of the coring arrangement and casting operation but these procedures are not described as they form no part of this invention and are well known to those skilled in the art.

Thus it will be seen that the end construction of this cast steel bolster has internal walls formed integrally with thet top, bottom and side walls of the bolster to surround and define the mounting chambers for the friction devices. There internal walls are continuous and form spaced apart vertical webs 53 which extend transversely toward the longitudinal bolster center line throughout the full height of the bolster to flank the friction block chamber, then toward each other to form the rear wall 52 of the friction block chamber with the rear wall having an opening for the control spring. The webs have portions then extending from adjacent this passage toward the longitudinal bolster center line to form the Wall 45 and then extending toward each other to form the rear wall 48 for the spring chamber. The web portions that extend to form the wall 45 have integral extensions merging with the top wall of the bolster to form the Walls 69 that flank the guide chamber.

It is important to note that while the top, bottom and side wall portions of the friction block 55 are intended to cooperate with the adjacent portions of the main friction block housing to provide a proper guiding action for the friction block, not infrequently it has been found in practice that excessive play exists between this main portion of the friction block and its surrounding housing.

The present arrangement is of the general class which seeks to take advantage of the unusual characteristics of an axially loaded friction damping system for controlling bolster movements and it has been found that prior art arrangements in this general class have not fully realized the inherent advantages of such an axially loaded friction block system, primarily due to the play of the friction block within its protecting and guidinghousing, and also because slight errors in the alignment of the friction housing with respect to the bolster side wall were found to invariably appear. As described above, the integrally cast construction of the present invention avoids misalignment of the friction housing. Coupled with this fact, however, is the fact that the friction block is formed with'the rearwardly extending guide portion 56 and this arrangement has been found to provide unusually effective guiding action for the friction block irrespective of the fact that some degree of play exists between the main body of the friction block and its housing. The rearwardly extending guide arrangement more than doubles the overall rearward dimension of this portion of the friction block and cooperates with the side walls 69 of the guide housing to prevent lateral play and with the adjacent portion of the top wall 33 of the bolster to prevent vertical play. Experience shows that the guiding and aligning action resulting from the combination of the friction block guide portion 56 with a friction block that is mounted in a friction housing directed exactly normal to the plane of the bolster side wall 35 and hence normal to the plane of the wear plate 32 results in vastly superior performance characteristics for the friction damping system.

Other advantages of the integrally cast bolster arrangement reside in the fact that the friction housing is defined at its top and bottom regions by the top and bottom bolster walls 33 and 34, respectively, and thus the integral construction while maintaining all strength requirements provides a friction housing of increased size. Thus the friction block and rearwardly extending guide may be of maximum cross sectional dimension and of even more importance is the fact that a large diameter spring may be employed. The increased spring diameter increases the bearing area subjected to spring pressures and effects a more even distribution of these pressures and in addition this larger spring exerts a better longitudinal aligning action.

For the purposes of shipping, handling and installation an elongated tapered keying element or sword 64 is provided. The side walls 60 of the guide housing are formed with aligned slots and these slots together with the slots 63 provided in the side arms of the guiding portion 56 of the friction block cooperate with the sword 64 to confine the friction block entirely within the housing 40. Thus as shown in Figs. 8 and 9 the front face of the friction block is slightly behind the side wall 35 of the bolster.

It will be remembered that the free height of spring 50 is somewhat greater than its height under loading conditions and therefore the control spring must be compressed during installation.

The parts are assembled simply by inserting the control spring 50 into the spring barrel 39 until the spring seats against the rear wall 48 thereof. The friction block 43 is then oriented appropriately and telescoped over the forward end of the spring so that the spring also seats in the circular recess 57 formed in the block and so that the guide portion 56 is aligned with the guide housing 41. Any suitable means known to those skilled in the art may be employed for compressing the friction block sufliciently to permit the sword to be inserted through the slots 65 and 63. Thus the friction blocks are securely retained entirely within the housings formed in the bolster and the bolsterv may be maintained in this assembled relationship during shipping and installation.

A suitable hole 66 is provided at the outer end of sword 64 and is adapted for engagement with an impact tool of any suitable form to permit the sword to be withdrawn to release the friction apparatus for cooperation with the wear plates 32 carried by the side frame columns. The tapered sword and cooperating slots are also arranged to facilitate the insertion of the sword and here again any suitable impact tool may be employed to force the sword into its locking position.

The problem of coring can be further simplified by slightly modifying the basic arrangement shown in Figs. 1 to to such an extent that the bolster center rib serves as the spring seat. Fig. 11 illustrates such a modified arrangement and while a longer spring, necessitating redesign, is shown in this figure, the increased length of the spring barrel 39 can be compensated by the use of a spacer plate (not shown) of suitable thickness between the center rib and control spring.

Thus it will be seen that the objects of the invention have been accomplished in that the integral construction of the bolster not only simplifies manufacturing and handling problems but permits a larger sized friction housing since the top and bottom walls of the bolster also constitute the top and bottom Walls of the housing. In addition, it is possible to more accurately align the friction housings when they are cast integrally with the bolster and this more accurate alignment in combination with the unusually effective guiding action resulting from the guide portion 56 of the friction block permit the present invention to otfer a truly axially loaded friction system that takes full advantage of the various features of such a system.

It should be understood that the description of the preferred form of the invention is for the purpose of complying with Section 112, Title 35 of the U. S. Code, and that the appended claims should be construed as broadly as the prior art will permit.

I claim:

1. In a railway car truck of the type including a cast steel bolster having side, top, and bottom walls, said bolster having each of its ends resting on a plurality of springs for vertical movement between the columns that flank the bolster opening of the side frame and with a friction producing device incorporated in each bolster end for cooperative engagement with a wear plate pro vided on the adjacent side frame column, which friction device includes a non-circular friction block filling substantially the full height of the bolster, and a substantially horizontal control spring urging the friction block outwardly against said wear plate, the combination with said bolster end of a housing forming a friction block chamber facing said wear plate through an opening extending the full height of the bolster side wall and a spring chamber communicating with said friction block chamber, and comprising vertically extending internal housing Walls integrally formed with the side, top, and bottom Walls of the bolster, said housing walls forming spaced apart vertical webs which extend first transversely toward the longitudinal bolster center line throughout the full height thereof to flank said friction block chamber, then toward each other throughout the full height of the bolster to form a rear wall for said friction block chamber, with said rear wall having a central passage for receiving said control spring, said webs having spaced apart complemental extension portions then extending transversely from adjacent said central passage toward the longitudinal bolster center line to flank said spring chamber and again toward each other to merge and form a rear wall for said spring chamber, said housing providing integral internal reinforcement structure bridging the opening in the bolster side wall.

2. The arrangement of claim 1 wherein said friction block has an integral guide projection extending rearwardly from the upper end thereof and the complemental extension portions of said webs also extend vertically to form spaced apart parallel web portions that merge integrally with the top wall of said bolster and define a chamber for receiving said projection in guiding coaction with said last-mentioned web portions.

3. The arrangement of claim 1 wherein the top and bottom walls are each of uniform thickness and directly border the upper and lower extremities of said friction block chamber.

References Cited in the file of this patent UNITED STATES PATENTS 1,452,529 Scheibli Apr. 24, 1923 2,340,928 Busch Feb. 8, 1944 2,434,858 Maatman et al Jan. 20, 1948 2,437,359 Pierce Mar. 9, 1948 2,471,481 Dath May 31, 1949 2,682,232 'Wulfi June 29, 1954 2,737,905 Holland et al. Mar. 13, 1956 

